1Earth and Environmental Science Department, Vanderbilt University, Nashville, TN,
2Space Science and Engineering Center, University of Wisconsin–Madison,
3German Meteorological Service (DWD), Offenbach, Germany
4Collecte Localisation Satellite (CLS), Toulouse, France
5European Space Agency (ESA-ESRIN), Frascati, Italy
6Institute for Space Sciences, Freie Universität Berlin, Germany
7Swedish Meteorological and Hydrological Institute (SMHI), Norrköping,
8Informus GmbH, Berlin, Germany
anow at: EUMETSAT, Darmstadt, Germany
bnow at: Geoforschungszentrum (GFZ), Potsdam, Germany
Received: 17 Sep 2016 – Discussion started: 19 Oct 2016
Abstract. The microwave radiometers (MWRs) on board the European Remote Sensing Satellites 1 and 2 (ERS-1 and ERS-2) and Envisat provide a continuous time series of brightness temperature observations between 1991 and 2012. Here we report on a new total column water vapour (TCWV) and wet tropospheric correction (WTC) dataset that builds on this time series. We use a one-dimensional variational approach to derive TCWV from MWR observations and ERA-Interim background information. A particular focus of this study lies on the intercalibration of the three different instruments, which is performed using constraints on liquid water path (LWP) and TCWV. Comparing our MWR-derived time series of TCWV against TCWV derived from Global Navigation Satellite System (GNSS) we find that the MWR-derived TCWV time series is stable over time. However, observations potentially affected by precipitation show a degraded performance compared to precipitation-free observations in terms of the accuracy of retrieved TCWV. An analysis of WTC shows further that the retrieved WTC is superior to purely ERA-Interim-derived WTC for all satellites and for the entire time series. Even compared to the European Space Agency's (ESA) operational WTC retrievals, which incorporate in addition to MWR additional observational data, the here-described dataset shows improvements in particular for the mid-latitudes and for the two earlier satellites, ERS-1 and ERS-2. The dataset is publicly available under doi:10.5676/DWD_EMIR/V001 (Bennartz et al., 2016).
Revised: 28 Jan 2017 – Accepted: 20 Mar 2017 – Published: 12 Apr 2017
Bennartz, R., Höschen, H., Picard, B., Schröder, M., Stengel, M., Sus, O., Bojkov, B., Casadio, S., Diedrich, H., Eliasson, S., Fell, F., Fischer, J., Hollmann, R., Preusker, R., and Willén, U.: An intercalibrated dataset of total column water vapour and wet tropospheric correction based on MWR on board ERS-1, ERS-2, and Envisat, Atmos. Meas. Tech., 10, 1387-1402, doi:10.5194/amt-10-1387-2017, 2017.